Wikipedia:Reference desk/Archives/Science/2008 April 1
Science desk | ||
---|---|---|
< March 31 | << Mar | April | May >> | April 2 > |
Welcome to the Wikipedia Science Reference Desk Archives |
---|
The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages. |
April 1
[edit]Electricity
[edit]What is the difference between coloumbs and amperes? This is for my revision, so if someone could answer this ASAP I would be very grateful! :)
- New questions belong at the bottom of this page, not the top. However, cloumbs are units of electric charge, while amps measure how fast that charge is flowing from one location to another. See coulomb and ampere for the details. StuRat (talk) 11:20, 7 April 2008 (UTC)
Smelly puddle
[edit]<moved from misc desk> While the snowbanks from winter are melting away in spring, puddles of water will form on the roads and streets. Occasionally, the water in these puddles will give off a very nasty, stinky odour. I can't really think of a comparison with the smell, but it is a sharp, repulsive smell. However, the smell does go almost completely away after a while. What describes this phenomenal? Is it some sort of bacteria in the water? Thanks. Acceptable (talk) 20:57, 30 March 2008 (UTC)
- One guess, an animal (hopefully) has defecated in the snow, it froze into a nice little popsicle, and then, when it warmed up, it melted into a nice bit of "mud". This will be quite fragrant until the bacteria break it down in a few days. StuRat 00:47, 1 April 2008 (UTC)
Apparent multiplying of mercury in body
[edit]A friend was telling me of how much his wife suffers from mercury poisoning,and one odd thing stoof out - it's taken years for it to get out of her system. Does it multiply by forming compounds with other things in the bloodstream or something? Does the mercury alter other cells? Or what? When he talks about how she has to swear it out, how the smell is on her clothes & such, and other things, it seems like the small amount of mercury she has shouldn't take tht long to get out.209.244.187.155 (talk) 00:05, 1 April 2008 (UTC)
- Smell? SMELL? What does it smell like?
- When liquid mercury is spilled, it forms droplets that can accumulate in the tiniest places; these droplets can emit vapors into the air that we cannot see or smell. —Preceding unsigned comment added by 79.76.208.103 (talk) 00:15, 1 April 2008 (UTC)
- It's not that it smells, sorry; I just associate that witht he fact she has to take two long showers a day, soak in a sauna, etc. - there are other reasons for showering besides smell. :-) But, the main question is, what does the mercry do in the body that causes it to take so long to get out?209.244.187.155 (talk) 00:28, 1 April 2008 (UTC)
- Which oaths does she use when swearing out mercury? Is it like "Out, damned spot!"? Edison (talk) 00:29, 1 April 2008 (UTC)
- I wonder why she would have guilt over the mercury. Did she steal it? --Bowlhover (talk) 03:23, 1 April 2008 (UTC)
- Without treatment for mercury poisoning, namely chelation therapy, the mercury will, indeed, take a very long time to leave the body. This is true of all heavy metals. The kidneys don't filter them from the body, so not much is removed in urine. I also don't believe a significant amount exits in respiration or sweat. This leaves things like skin flakes, hair, and fingernail clippings as the rather slow way to remove mercury from the body. StuRat 01:03, 1 April 2008 (UTC)
- I once heard of a case where someone swalled metallic mercury and for some reason it stayed in their stomach and did not pass through to the intestines. This person was slowly being poisoned, not by the metallic mercury but by the vapours that came up from his stomach and then went into his lungs. I'm not sure but I think he survived.--Shniken1 (talk) 01:40, 1 April 2008 (UTC)
- As for whether mercury can multiply over time, the answer is a definite no. Chemical reactions can only change the arrangements of atoms inside a compound, not the identity of the atoms. Iron, for example, cannot change into mercury. Unless your friend's wife absorbed additional mercury, the amount of mercury inside her body will decrease by the same amount that was expelled from her body. --Bowlhover (talk) 03:23, 1 April 2008 (UTC)
- I assumed the questioner was asking if it can accumulate over time, which does happen if there is a continual source of mercury. StuRat (talk) 15:38, 1 April 2008 (UTC)
- One of the more bizarre radiographs I've ever come across involved an individual who had – for no good reason and presumably while under the influence of intoxicating substances – injected himself intravenously with liquid metallic mercury. He had presented to the emergency room with persistent cough and a chest x-ray was ordered. His lungs were speckled throughout with bright, x-ray opaque spots. Here's a similar image: [1]. Google for 'mercury embolism' or 'mercury emboli' to find more case reports. TenOfAllTrades(talk) 14:57, 1 April 2008 (UTC)
- A few years ago, I remember reading a news story about a mentally-ill man who had some sort of obsession with mercury and wound up in hospital after swallowing and skin-popping vast amounts of the stuff over a long period of time. IIRC, the hospital had to close down a whole ward for decontamination afterwards. --Kurt Shaped Box (talk) 22:20, 1 April 2008 (UTC)
- chelation therapy is unproven science, the evidence of it's effectiveness is tenuous at best, you hear about it mostly along side other "alternative" medicines. -- JSBillings 11:21, 1 April 2008 (UTC)
- I was under the impression that it is proven for certain limited uses (the article says it's licensed by the FDA), but that it's touted for uses where it's not proven (e.g. in autism). 81.174.226.229 (talk) 11:48, 1 April 2008 (UTC)
- Both of the above responses are correct—chelation therapy is an appropriate, approved, and demonstrated effective treatment for certain types of metal poisoning (especially the heavy metals lead, arsenic, and mercury). It is also promoted by quacks for a range of other conditions for which it has no demonstable efficacy, including (and especially) autism spectrum disorders. TenOfAllTrades(talk) 14:57, 1 April 2008 (UTC)
Cassette speed
[edit]I've just bought Who's Next through the iTunes store and for whatever reason, I decided to compare it with my old cassette tape recording. I started to play both recordings at the same time. The first thing I noticed was that it sounded awful. The cassette was very noticeably higher than the aac. Then, it began to sound worse—the cassette was going much faster than the iPod. The two together made me suspect that my stereo is perhaps playing the cassette a bit fast, so I was wondering, is this normal? Are recordings sped up/slowed down from the originals, perhaps to fit more music on a smaller space? Or is it just my stereo? 66.21.215.126 (talk) 00:33, 1 April 2008 (UTC)
- Cassette players can easily go the wrong speed. You could check the belts to see if they are on the wheels properly and are not loose. Graeme Bartlett (talk) 00:58, 1 April 2008 (UTC)
- Or, the recordings could be different. Sometimes, for obscure marketing reasons, record labels will release different versions of the same album via different mediums (CD, cassette, vinyl, etc). Nimur (talk) 15:04, 1 April 2008 (UTC)
Turning a frog into a prince
[edit]Okay, say I had a frog and I wanted to make him a prince with *no* magic. In other words, say the technology existed to re-configure the cells changing frog organs into human ones, though not instantly like when a fairy godmother waves her magic wand. What would be the most difficult organ to change, assuming the frog had to be opened up to do this with? I'm guessing the stomach, so the guy wouldn't have to eat flies all his life, but I'm not sure. Would anything need added, or could something in the frog be used? Finally, how tall would this guy be when it was all said and done? Would he be tall enough to be a match for Thumbelina, anyway? (My question for April Fools' Day - but I am curious, too. Just don't say you can't give out medical advice :-)Somebody or his brother (talk) 02:35, 1 April 2008 (UTC)
- Biggest problem I see with your plan is finding a country willing to have an ex-frog as regent.--Shniken1 (talk) 05:22, 1 April 2008 (UTC)
- I'm not an expert in frog physiology, but I'd say the brain would be the most difficult organ to change. Not only would the physiological changes have to occur, but the learning necessary to have even a physically functioning individual would take decades. This won't be a problem if you don't mind having a brainless prince, which wouldn't be much different than we've got now in the States *rimshot*. — Ƶ§œš¹ [aɪm ˈfɻɛ̃ⁿdˡi] 05:35, 1 April 2008 (UTC)
- Agree, I don't think you can stuff that much neurons in such a small space to reproduce human intelligence--Lenticel (talk) 05:54, 1 April 2008 (UTC)
- I may have misunderstood the question, but I think the question asker is wanting to change a frog into a normal sized and I guess fairly normal looking human. While the brain would indeed be a big problem, I have to say the whole thing sounds fairly unlikely to me. For starters, where would all the mass come from? It sounds to me like you're planning to more or less create a human out of thin air, the existing frog is most irrelevant Nil Einne (talk) 06:36, 1 April 2008 (UTC)
- The user wanted a thumbelina escort so I think he/she means a frog-sized prince. Anyways there are lots of problems to where the mass could come from. The ideal mass would come from a fresh male human body with princely qualities. Note that neurons don't divide so we can't expand the frog's brain into the human skull housing.--Lenticel (talk) 07:01, 1 April 2008 (UTC)
- Perhaps the frog's brain could be removed and replaced with technology. I suppose an AI could be used, but I prefer a wireless link to an existing human brain in a jar. If the brain previously belonged to a prince you may have also solved the royalty problem. APL (talk) 22:23, 1 April 2008 (UTC)
- The user wanted a thumbelina escort so I think he/she means a frog-sized prince. Anyways there are lots of problems to where the mass could come from. The ideal mass would come from a fresh male human body with princely qualities. Note that neurons don't divide so we can't expand the frog's brain into the human skull housing.--Lenticel (talk) 07:01, 1 April 2008 (UTC)
- I may have misunderstood the question, but I think the question asker is wanting to change a frog into a normal sized and I guess fairly normal looking human. While the brain would indeed be a big problem, I have to say the whole thing sounds fairly unlikely to me. For starters, where would all the mass come from? It sounds to me like you're planning to more or less create a human out of thin air, the existing frog is most irrelevant Nil Einne (talk) 06:36, 1 April 2008 (UTC)
- Agree, I don't think you can stuff that much neurons in such a small space to reproduce human intelligence--Lenticel (talk) 05:54, 1 April 2008 (UTC)
- I'm not an expert in frog physiology, but I'd say the brain would be the most difficult organ to change. Not only would the physiological changes have to occur, but the learning necessary to have even a physically functioning individual would take decades. This won't be a problem if you don't mind having a brainless prince, which wouldn't be much different than we've got now in the States *rimshot*. — Ƶ§œš¹ [aɪm ˈfɻɛ̃ⁿdˡi] 05:35, 1 April 2008 (UTC)
- Biggest problem I see with your plan is finding a country willing to have an ex-frog as regent.--Shniken1 (talk) 05:22, 1 April 2008 (UTC)
- I suspect the easiest way to turn a frog into a prince is to feed the frog to a pregnant queen. -- JSBillings 11:12, 1 April 2008 (UTC)
- There is, just, the technology now to reengineer living organisms in vivo, although changing a few proteins is the very limit of that right now. Recombinant DNA technologies, the mechanisms used in gene therapy, and in particular viral vectors allow you to alter the DNA of a living, mature organism. But doing this to affect wholesale change is a mammoth task (it's unfeasably huge, really), as you need to change every adult stem cell, and with a genetic payload vastly greater than a virus can carry. Even if you could jump that huge hurdle, you'd find the design of the intermediate forms of the frog-man would have to be very carefully done, so that each form was viable (just changing frog heart cells in to human heart cells won't make it grow a human heart). And even if you can do that, these genetic changes only apply when the cells are renewed. Nerve cells generally aren't, so your completed frog-man would still have the brain and nervous-system of a frog (it couldn't regulate its blood pressure, never mind move or think). You could engineer your organism to grow a fresh new CNS in parallel, a human one that the prince could use. But this transformation is so fundamental that you really can't say that the frog has turned into a prince, but rather that you've spent (wasted) a trillion dollars growing a human on the back of a frog. As you totally control the cell divsion, you can make frogPrince any size you want; as he's not much use to a princess unless he's normal size (or a big bigger, if you know what I mean) then he'd probably be a regular guy, except with the remnant of a little frog on his back. -- Finlay McWalter | Talk 12:42, 1 April 2008 (UTC)
- Oh, I forgot. You also need to worry about telomere length, genetic damage, and other gene-level aging and cancer-causing problems. Really it's much more efficient for the princess to shop for a regular prince on the internet (Horsefacebook.com)' then she'll have a prince and a frog. -- Finlay McWalter | Talk 13:00, 1 April 2008 (UTC)
Once you turn your frog into a man, you still have the problem that he's not a prince. You would have to find a font of honour to do that job - a reigning King or Queen, for example, and persuade them to do the deed. Good luck! - Nunh-huh 21:49, 1 April 2008 (UTC)
- I thought of another good way to turn a frog into a prince: Crown the frog's father King. -- JSBillings 23:38, 1 April 2008 (UTC)
- The problem remains though that you're going to have to convince someone to take a frog or a frog-human (presuming you did the same for the father or mother) as king or queen. Given that on the whole, the monarchies of this world seem to be being reduced, not increased, I don't think it would be a simple matter even without the complexity of your candidate being a frog/frog-human Nil Einne (talk) 11:45, 2 April 2008 (UTC)
- Yes I think that there would be a chance that a number of constituencies may elect a frog/human but I find it unlikely that said frog would be able to become prince (barring some Coup d'état, in which case he would probably name himself King not prince).
PS: apologies to people from those constituencies reading this.. Shniken1 (talk) 23:11, 2 April 2008 (UTC)
- On second though you're right. I don't know about the examples you mentioned, but I think it would be fairly easy to convince some small town or whatever to elect a frog-human as an honourary prince/king/queen for publicity purposes. I mean let's face it, if you do manage to do this, there will be great interested in this frog-human. Of course you will also have to put up with all the religious and green protestors Nil Einne (talk) 06:56, 3 April 2008 (UTC)
Did excess water intake leads to kidney troubles?
[edit]I used to drink more & more water since long time. seeing this my mom is claiming that excess water intake leads to kidney truble as the water u drink will undergo filteration by them. may be she's true to some extent b'coz i used to urinate more frequently than any other else. that shows that my kidneys are working more as i'm drinking more water. so now should i stop taking that much water in order to safegaurd my kidneys. or is it just our hype? Temuzion (talk) 04:58, 1 April 2008 (UTC)
- You might want to read our article on water toxicity. Wisdom89 (T / C) 05:04, 1 April 2008 (UTC)
- Note that the amount listed in the above article is more than 10 liters (around 2½ gallons) in a few minutes. You probably don't drink nearly as much water so quickly. The kidneys do process the water, true, but processing large amounts of water doesn't damage them. To the contrary, this may help to prevent kidney stones, which can indeed damage the kidneys, by diluting the materials from which kidney stones form to below the concentration where they come out of solution and form stones. Numerous studies have recommended drinking large quantities of water, on the order of 10 cups a day, for this and other reasons. The downside, of course, is that you will need to urinate more often. If you "hold it in", that could potentially cause a problem. So, assuming you drink around 10 cups a day and urinate as needed, you are correct and your mom is wrong. Go ahead and keep drinking water. StuRat (talk) 15:46, 1 April 2008 (UTC)
- Please note that unusual thirst can be a sign of diabetes, so it is very important that you discuss this question with a doctor. The same is true for all other health matters – reference desk volunteers cannot give medical advice. --169.230.94.28 (talk) —Preceding comment was added at 16:00, 1 April 2008 (UTC)
- U should know a point that this water drinking is not because of thrist but it was because i want to look attractive. I got many pimples on my face when i don't have the habit of taking so much water. But after starting intake of water in this way my pimples reduced & the face indeed becoming smooth. This was encouraging me to take more & more water. So r u sure that "over" processing of water won't lead to any kidney trouble. If u confidently say 'yes', I'll continue the habit. No question of diabetes once again I'm saying this because our family has a habit of consuming very less oil in our daily intake. My grand father has diabetes. So my father is taking all the measures he know in order to reduce the diabetic attack. Still at this 50+ age my father is very relaxed regarding sugar levels & we all are following that measures too. So now plz after considering all these situations suggest me the way I should go...whether to carry on or to stop? Temuzion (talk) 04:33, 2 April 2008 (UTC)
- We can’t give you medical advice here. Talk to a doctor. --S.dedalus (talk) 05:31, 2 April 2008 (UTC)
- How much water to drink each day isn't medical advice, it's dietary advice. With that in mind, go ahead and drink up to 10 glasses of water each day. It's good for you. Also, to help reduce pimples avoid fatty foods, especially trans-fats, which can clog pores. StuRat (talk) 13:08, 2 April 2008 (UTC)
- Actually, although it's commonly believed by the general public that a diet high in fatty is a contributing factor, the evidence for that is quite weak. Check out Acne vulgaris. But fatty foods, particularly trans fats are bad for you in a number of ways so it would be a good idea to limit their consumption (or eliminate as far as possible in the case of trans fats). But particularly if you have a family history of diabetes, I wouldn't reduce it too much if it means your eating more refined sugars instead. Stress is definitely a contributing factor so whatever you do, don't worry too much about it, you'd just make it worse. Nil Einne (talk) 06:51, 3 April 2008 (UTC)
- Can you cite any studies which disprove the link with trans-fats ? I'm skeptical that many thorough studies have been done, since there's no profit motive in proving that diet can prevent acne (although those selling acne meds might have a considerable profit motive to disprove this link). On the other hand, there are billions to be made by "proving" that medications can fight acne. The link is readily apparent for me. If I eat trans-fats, I have acne the next day. If I avoid them, my skin stays clear. I believe many studies in the past for fats or chocolate have failed to pick up the trans-fat link, since trans-fats are present in some fatty foods and chocolate, but not all. Those studies might tend to use fatty foods and chocolate without trans-fats, since it's unethical to give patients something harmful, and trans-fats are known to be harmful in other ways. StuRat (talk) 13:26, 3 April 2008 (UTC)
Drinking a lot of water is not medical advice, and the recommendation is probably a historical canard, see this BMJ article. I agree that it matters a lot about the reason why one would drink so much water. If it is out of persistent severe thirst, some medical problems tend to need looking into (diabetes mellitus, diabetes insipidus); if it is a bit of an obsession, OCD or psychogenic polydipsia may come into play. But on the whole, drinking a lot of water is not known to damage the kidneys. Absolutely excessive water drinking that exceeds the body's free water clearance may lead to hyponatremia, but in young people this is pretty hard. JFW | T@lk 23:37, 5 April 2008 (UTC)
What animals have adrenaline?
[edit]Is there some equivalent for insects, reptiles, etc? Mr.K. (talk) 08:56, 1 April 2008 (UTC)
- I would imagine reptiles have adrenaline, along with any other vertebrates. You should read into the autonomic nervous system. —Preceding unsigned comment added by Mark PEA (talk • contribs) 17:12, 1 April 2008 (UTC)
- Adrenaline (or epinephrine) is part of the monoamine neurotransmitter family. Animals throughout metazoa have various combinations of these. Some, for example octopamine, are neurotransmitters in invertebrates but only a trace amine in mammals. PMID 17142674 ←This paper interestingly discusses the genetic diversity and phylogeny of monoamine transporters throughout metazoa. If you're looking for the non-mammalian equivalent of the fight-or-flight hormonal action of adrenaline, PMID 17874113 deals with the "Evolutionary origin of autonomic regulation of physiological activities in vertebrate phyla". According to that paper, 5-HT plays the role in Aplysia that norepinephrine plays in mammals, for example. — Scientizzle 18:52, 1 April 2008 (UTC)
Do we have an article on this ? It's a form of renal/kidney failure my Dad had. If I understand it correctly the kidneys first remove just about everything from the bloodstream, then put the water back in. In normal kidney failure the first step doesn't work, while in high output kidney failure the second step fails, leading to consumption of large quantities of water and production of large amounts of dilute urine. This condition is less serious than low output kidney failure because the toxins and wastes are still removed. StuRat (talk) 16:01, 1 April 2008 (UTC)
- We don't have a separate article on it, but it's mentioned in the acute renal failure article (as nonoliguric renal failure). - Nunh-huh 22:03, 1 April 2008 (UTC)
- All I see there is the phrase "although nonoliguric ARF may occur", is that all we have on Wikipedia ? StuRat (talk) 03:17, 2 April 2008 (UTC)
- That's all I see. The ARF article should be expanded, and that's probably where the information belongs -- it's a type of manifestation with implications for treatment but not so important in terms of etiology or for classification. - Nunh-huh 04:27, 4 April 2008 (UTC)
- OK, I'll add some info there. Is my description above essentially correct ? StuRat (talk) 14:21, 4 April 2008 (UTC)
- The description of the workings of the kidney is correct, though simplified (might be nice in the kidney article). It's not quite right, though, to imply there's a perfect correspondence between disorders of filtration with low output renal failure on the one hand and disorders of resorption and high output renal failure on the other. While waiting for a renal expert, I'd suggest adding the following facts to the article: [1] oligouric renal failure = low output renal failure; non-oligouric renal failure = high output renal failure, with the usual amount of urine output qualifying as high output to be 400-600 ml/day. [2] changes in urine output do not correlate well with changes in GFR. [3] about 50-60% of all causes of ARF are nonoliguric. [4] the amount of urine produced may help to indicate the cause of renal failure (though these are only indications) [4a] anuria, in which <100 mL/day of urine is produced, can suggest urinary tract obstruction, renal artery obstruction, rapidly progressive glomerulonephritis, or bilateral diffuse renal cortical necrosis. [4b] oliguria, in which 100-400 mL/day of urine is produced, may suggest prerenal failure or hepatorenal syndrome. [4c] non-oliguria, in which the kidneys produce >400 ml/day of urine, may suggest acute interstitial nephritis, acute glomerulonephritis, partial obstructive nephropathy, nephrotoxic and ischemic ATN, radiocontrast-induced ARF, or rhabdomyolysis. -Nunh-huh 20:23, 4 April 2008 (UTC)
- Thx. What are ATN and GFR ? StuRat (talk) 02:34, 5 April 2008 (UTC)
This sounds like diabetes insipidus. (ATN is acute tubular necrosis; GFR is glomerular filtration rate.) Axl (talk) 09:19, 5 April 2008 (UTC)
- Interesting. How does one distinguish between this condition and high output renal failure ? StuRat (talk) 14:05, 5 April 2008 (UTC)
Looking at it this is not necessarily acute renal failure. Chronic kidney disease does not typically lead to oliguria, but the kidney may be poor at excreting solutes and still cause uraemia and metabolic disturbances. I think StuRat's explanation is very credible. JFW | T@lk 23:40, 5 April 2008 (UTC)
- Diabetes insipidus is not acute renal failure-- but it is in the differential diagnosis of high urine output.
- AFAIK high output acute renal failure (HOARF) isn't really that much different than oliguric ARF-- but it could be an article.
- Major differences as I understand them...
- In HOARF volume overload is not a problem. The opposite may occur-- volume deficit, i.e. "dehydration".
- I think the prognosis is a bit different-- 'cause in HOARF there is renal tubular dysfunction (in addition to some glomerular dysfunction).
- The major difference between diabetes insipidus and HOARF -- glomerular function. In HOARF the serum creatinine will be elevated. In diabetes insipidus (DI) it should be normal. The conditions are quite different. DI, etiologically, may not be related to the kidney at all, i.e. central DI.
- Nephron T|C 12:57, 7 April 2008 (UTC)
- Thanks.
So, has anyone changed any articles yet or created new articles ? If so, which ones ? StuRat (talk) 14:17, 7 April 2008 (UTC)
SDS-PAGE and Size Exclusion Chromatography
[edit]Before running a protein sample on an SDS-PAGE gel, you mix the sample with SDS and the SDS "binds" to the protein. There is also SDS in the gel I believe. My question is -- Let's say you mix a protein with SDS as above, but instead of running this sample on a gel, you run it through an SEC column -- Would the SDS stay associated with the protein or get separated from it? ike9898 (talk) 16:51, 1 April 2008 (UTC)
- Ok, well, what you describe is never really done - and I think the reason is because the SDS will bind/coat the protein (I think in a 4:1 ratio if I remember correctly) and force the protein to extend into a linear rod like configuration. If you ran the sample over a gel filtration column using an inert buffer like HEPES pH 7.4, the SDS would remain with the protein, but the protein would probably run slower than the folded globular configuration since it would remain outside the pores. So, it might work, but you wouldn't know where the protein would come out - perhaps in the void volume. Wisdom89 (T / C) 17:35, 1 April 2008 (UTC)
- To clarify, I am asking because we have a sample that is giving us trouble with our SEC method. It is a sample of gelatin and a lot of the sample is coming off the column at a retention time that would indicate a MW of greater than 500 kDa. I think that this represents multiple peptides of less than 100kDa associated non-covalently. I'd like get the MW distribution of peptides when they are not associated like this. ike9898 (talk) 19:19, 1 April 2008 (UTC)
- Gotcha, in that case I would use an non-ionic detergent such as Triton X-100 in your buffer. Also, you could trying using a high sodium chloride concentration along with beta-mercaptoethanol to disrupt the aggregation. Wisdom89 (T / C) 19:24, 1 April 2008 (UTC)
How is DNA an acid?
[edit]Doesn't the phosphate make it a base? 128.163.170.163 (talk) 17:12, 1 April 2008 (UTC)
- Phosphate is the ionized form of phosphoric acid, if you look at the DNA molecule and see the negatively charged oxygens in the phosphate group, you might think of it as a base, but the oxygen is negatively charged because the hydrogen (H+) has dissociated. --Mark PEA (talk) 17:24, 1 April 2008 (UTC)
- Yes, since the proton in the phosphate dissociated, doesn't it make the DNA the conjugate base?128.163.170.163 (talk) 17:35, 1 April 2008 (UTC)
- Yup, pretty sure that's the definition of a conjugate base. Wisdom89 (T / C) 17:38, 1 April 2008 (UTC)
- To the annoyance of biochemistry students everywhere, the convention for diagramming biochemical acids is to show the proton already dissociated, and bases showing an extra proton, often signified by a H+. When I angrily asked my professor about this during my undergrad years, he told me that this is because at physiological pH, DNA (being acidic) has given up its proton. It makes some sense, because the conjugate base isn't really all that basic, so it sort of shows that the acid has taken action. Of course, realistically, the acid and conjugate base form of DNA are in constant equilibrium, with the balance being in favour of the conjugate base. And from an organic chemistry context, being able to see the conjugate base sure is helpful in drawing resonance structures that explain the molecule's acidity in the first place!Vance.mcpherson (talk) 00:10, 2 April 2008 (UTC)
Pulmonary artery
[edit]On an episode of Dexter, Rudy has a girl in a headlock and squeezes a her neck with his arm, claiming that he is blocking her pulmonary artery, cutting oxygen from her brain and that she will be unconscious in a matter of seconds. I know its a TV show, but is this at all true? If so, how long would a subject stay unconscious for? This is purely out of curiosity I might add; I'm not planning to kill anyone just yet ;) —Preceding unsigned comment added by Crazy joke (talk • contribs) 18:59, 1 April 2008 (UTC)
- The carotid arteries are those vessels which supply blood to the brain. Wisdom89 (T / C) 19:20, 1 April 2008 (UTC)
- The Pulmonary arteries are in the thorax near the lungs, so Rudy is way off. Yes, this WILL knock you out if your brain doesn't get oxygen. I'm sure if he held her long enough, he could cause permanent brain damage or death. However, I don't know how long it would take for the victim to recover. Paragon12321 (talk) 19:29, 1 April 2008 (UTC)
- How long would it take to recover from death? I would say an infinite amount of time. —Preceding unsigned comment added by 79.76.250.241 (talk) 00:48, 2 April 2008 (UTC)
- (edit conflict) If he really said "pulmonary", we have one more reason to support the writer's union. It's the carotid arteries that when occluded will cause unconsciousness. Some people never wake up from that, but almost everybody comes to in seconds with no lasting effects if the choke is maintained only briefly. Our article says that unconsciousness lasts for double the time the choke is held after the person passes out, unless they die, of course, or suffer permanent brain damage from ischemia. Other risks include physical damage to the neck itself, plaques in the arteries leading to stroke, and lung damage if you do it wrong. The guy's a serial killer, for cryin' out loud. Don't listen to him. --Milkbreath (talk) 19:31, 1 April 2008 (UTC)
- Yeah, I think it was the carotid arteries he said. To be honest I just remember the arteries bit. BTW, thanks Wisdom89, Paragon12321 and especally Milkbreath. All you guys on the ref desk are the best! Crazy joke (talk) 19:38, 1 April 2008 (UTC)
- I saw that episode, and I think you were right the first time, he did say "pulmonary". I remember thinking "don't they mean carotid" ? StuRat (talk) 20:29, 1 April 2008 (UTC)
- I just checked StuRat, and he does say carotid artery. Looks like they did their research. Anyway, thanks everyone. Crazy joke (talk) 20:52, 1 April 2008 (UTC)
- Where did you check ? Sometimes the script says one thing but the actors say another. StuRat (talk) 03:06, 2 April 2008 (UTC)
- I'd downloaded the episode a while back. Its episode 11 of season 1. Crazy joke (talk) 19:17, 2 April 2008 (UTC)
- Perhaps both of you are right. It's possible if this episode were from a DVD release for example, that it had been corrected if there was a mistake. I think this sometimes happensNil Einne (talk) 07:01, 3 April 2008 (UTC)
- I'd downloaded the episode a while back. Its episode 11 of season 1. Crazy joke (talk) 19:17, 2 April 2008 (UTC)
- Where did you check ? Sometimes the script says one thing but the actors say another. StuRat (talk) 03:06, 2 April 2008 (UTC)
alternative to chloroform
[edit]Another question, again out of curiosity. I'm writing a short story, actually. What would be an alternative to chloroform? It has to be something that could be used to knock someone out, but that is undetectable and non lethal? I found this yahoo answers question which suggested something that is detectable, but that is not unexpected, like opiates in a heroin user, benzodiazepines in a benzo addict, GHB in a GHB abuser or alcohol in an alcoholic. The problem with these, in the context of my short story, is that they are not readily available chemicals, except for the alcohol which would be pretty hard to get into someone quickly and stealthily. Any suggestions? It doesn't have to be a chemical, it just has to get them unconscious Crazy joke (talk) 19:38, 1 April 2008 (UTC)
- Nitrogen. They'll pass out without knowing anything's wrong. — kwami (talk) 19:45, 1 April 2008 (UTC)
- Anything that goes under the "instead of oxygen" category is going to fail "non-lethal". Wholesale replacement of a room's atmosphere? Not very likely. — Lomn 21:43, 1 April 2008 (UTC)
- Who said anything about likely? It's happened, though as you say, with lethal results. But chloroform would be lethal too in excess - question's in the timing. — kwami (talk) 00:08, 2 April 2008 (UTC)
- If there were easily available substances that could reliably be used to knock people out non-lethally, they would be used by criminals. (There is a myth that this actually happens on sleeping-car trains, but if you look for specifics, nobody has any. It doesn't happen. See this message board thread for an example of such a discussion. Apparently it's easier for people to believe that they fell victim to a chemically-armed crook than to a quiet one.)
- Of course a gaseous anesthetic will make someone unconscious, and so will replacement of oxygen in the air with something else; but, as already stated, it'd be very easy to kill the victim doing that unless you were very careful. --Anonymous, 00:33 UTC, April 2, 2008.
- Is there a particular reason you eliminate chloroform? (Might help with suggestions if you told us.) Pretty much any general anesthetic will knock someone out. The two "classics" are chloroform and (diethyl) ether. Note, however, that "non-lethal" is dependant on dose - one reason chloroform and ether aren't used as anesthetics anymore is that the amount needed to knock someone out is very close to the amount needed to kill them. If you let your characters have access to medical equipment, your best bet would likely be some medical anesthetic. (If it's rare enough, it would be "undetectable" in the fact that no one would likely test for it.)-- 128.104.112.85 (talk) 17:05, 2 April 2008 (UTC)
- Thanks all you guys! Yeah, I eliminated chloroform because its hard to come by and a bit old school. Saying that though, there are sites out there that tell you make your own chloroform. As Lomn and others pointed out, replacing all the air in a room is not practical, especially on a low budget. And chloroform risks killing the victim. Its important they don't die. If it helps the character is a teenager seeking revenge. She's a bit of a psycho and decides the best way to humiliate her cheating boyfriend is to knock him out and set him up. It has to be something believable though, as she later confesses to the police, so no Vulcan neck pinches! Unless of course that would work? Would it? BTW, (again from Dexter) would injecting something into the victim work? Dexter seems to have the nack of it. Anyway, a big thank you to everyone who contributed! You've given me some great ideas! Crazy joke (talk) 19:34, 2 April 2008 (UTC)
- Well, the old "blow to the head" trick seems to work often enough, though it's not usually "undetectable". Or, you could give the boyfriend some type of allergy or other medical condition that the girlfriend takes advantage of to knock him out (like epilepsy). Mixing alcohol with some medications may also have the effect you desire, though I don't know which ones. Heck, depending on what she's planning she might be able to just do it while he's sleeping. Hope that helps! -- HiEv 12:29, 3 April 2008 (UTC)
- Thanks all you guys! Yeah, I eliminated chloroform because its hard to come by and a bit old school. Saying that though, there are sites out there that tell you make your own chloroform. As Lomn and others pointed out, replacing all the air in a room is not practical, especially on a low budget. And chloroform risks killing the victim. Its important they don't die. If it helps the character is a teenager seeking revenge. She's a bit of a psycho and decides the best way to humiliate her cheating boyfriend is to knock him out and set him up. It has to be something believable though, as she later confesses to the police, so no Vulcan neck pinches! Unless of course that would work? Would it? BTW, (again from Dexter) would injecting something into the victim work? Dexter seems to have the nack of it. Anyway, a big thank you to everyone who contributed! You've given me some great ideas! Crazy joke (talk) 19:34, 2 April 2008 (UTC)
Gas mileage
[edit]I'm trying to determine my minivan's gas consumption under various conditions. I have a 6 cylinder, 3.8L engine which idles at about 600 rpm. I need to know volume of vaporized gasoline is injected into each cylinder during the intake stroke. Does it vary among different engines? So far I have determined that the van will travel about 30 ft per mL. I want to know how fast it is using gas when I am stopped. —Preceding unsigned comment added by 66.120.95.34 (talk) 20:04, 1 April 2008 (UTC)
- You want to know gas mileage while idling? The only way I can think of to measure this would be to fill up, let it idle for a few hours (so that a measurable amount of gas was used), then fill up again to measure. Then you can figure how much gas per hour is used while idling. Most people don't really care, tho. Why not just measure the mileage you get while driving? Friday (talk) 20:08, 1 April 2008 (UTC)
- Isn't the answer obviously 0 miles per gallon when idling? Nimur (talk) 21:56, 1 April 2008 (UTC)
- Well, yes. I should have said "usage" or something. Friday (talk) 21:57, 1 April 2008 (UTC)
- Isn't the answer obviously 0 miles per gallon when idling? Nimur (talk) 21:56, 1 April 2008 (UTC)
- The magic of google suggests a number between 0.5 and 1 gallon per hour while idling. Dragons flight (talk) 20:18, 1 April 2008 (UTC)
- It's clearly a pretty small number. A couple of winters ago, when our house was without power for several days, we hooked up a big (750W) inverter to our Dodge Caravan (with the 3.3L V6) and set it "fast idling" in the driveway. It ran for hours and hours with what I thought was a surprisingly small consumption of gas. (1/4 of a tank?)
- And I've thought about exactly the question posed here; I decided that if I were ever really interested, I'd wire into the solenoid valve on one of the fuel injectors and integrate the pulses. I'm pretty sure that modern electronic fuel injection systems run at a constant fuel pressure (unlike older mechanical fuel injection systems) so the integral of the injector's pulses should directly translate to fuel consumed. You could take a short-term moving average and display instantaneous fuel consumption or integrate over time and come up with total volume consumed. You'd have to wire-in carefully, though, lest you cause severe, expensive damage to your car's engine management computer. That's why I haven't performed the experiment yet.
- Something else you could try is to install a flow meter into the pipe between the gas tank and the engine (this is how the Mythbusters calculated their gas mileage). That way, you can get a direct measurement of how much gas you're using, without having to do any fancy math. — QuantumEleven 14:24, 2 April 2008 (UTC)
- Depending on how the car is designed, that may or may not work. Some cars have the mechanical equivalent of a shunt regulator to regulate the pressure so they pump more gas than they need and dump the excess back into the tank (via a 'return" line). And cobbling a flow meter into the high-pressure gasoline line sounds like a much more dangerous experiment than tapping onto a 12V solenoid wire.
Hedgehogs and breeding
[edit]In hedgehogs, who takes care of the young, the female, the male or both? Leptictidium (mammal talk!) 20:25, 1 April 2008 (UTC)
- Yes but, first, you have to ask how hedgehogs make love! —Preceding unsigned comment added by 79.76.250.241 (talk) 01:05, 2 April 2008 (UTC)
- I used to think they were silent creatures, but then I realized that they were affected by Sonic interactions. DMacks (talk) 03:01, 2 April 2008 (UTC)
- Refdesk regular Kainaw's user page asserts "when it comes to hedgehogs, there are few people who know more than I do", so you might ask him/her if you don't get a good answer here. --Sean 13:40, 2 April 2008 (UTC)
- The female takes care of the young. After mating, the males don't hang around. If, because of confinement, the male is near when the young are born, he will attempt to kill them. There are rare exceptions (just as there are cases where a dog raises a baby kitten). However, the rule is that the male is nowhere to be found once the babies are born.
- There is always the joke about hedgehogs making love. Most people do not know that the male's penis slightly higher up his abdomen than where you'd expect his bellybutton to be. If humans were the same, our penis would be about two inches above our belly button. Because of this, the male doesn't have to completely mount the female in the same way that other mammals do. He only has to get half his body on top. -- kainaw™ 12:24, 3 April 2008 (UTC)
Spider eyes
[edit]Do spiders have eyelids? If not how do they keep them their eyes moist or protected? 200.127.59.151 (talk) 22:16, 1 April 2008 (UTC)
- Well, some have no eyes, others have
Compound eyesthat don't have any eyelids. --Lenticel (talk) 22:26, 1 April 2008 (UTC)- Spiders have compound eyes? They don't look like compound eyes. Is there an anatomy drawing of spider eyes somewhere? 200.127.59.151 (talk) 22:51, 1 April 2008 (UTC)
- If you shine a laser at a big wolf spider you only see a pair of eyes in front but almost to the sides. The reflected light is fairly intense and this is how I find spiders at night and other little creatures. 71.100.173.69 (talk) 23:19, 1 April 2008 (UTC)
- I believe some spiders only have simple eyes, but some have both. — kwami (talk) 00:09, 2 April 2008 (UTC)
- I'm sorry but this needs investigation. I can't find a reference that says spiders have compound eyes unless you take compound as meaning multiple individual eyes but that doesn't seem to fit our article's definition (or am I mistaken?). And it leaves the question of how the eyes are cleaned or moistened. 200.127.59.151 (talk) 01:44, 2 April 2008 (UTC)
- I retracted the compound eye part, it seems that spiders evolved simple eyes per [2]. Somebody should fix the Spider anatomy article.--Lenticel (talk) 04:06, 2 April 2008 (UTC)
- Do eyes necessarily need to be moist in order to function (ours do - but our eyes are not representative of all eyes)? I *think* I've seen spiders cleaning their eyes with their forelimbs - flies certainly do that. --Kurt Shaped Box (talk) 01:50, 2 April 2008 (UTC)
- I'm sorry but this needs investigation. I can't find a reference that says spiders have compound eyes unless you take compound as meaning multiple individual eyes but that doesn't seem to fit our article's definition (or am I mistaken?). And it leaves the question of how the eyes are cleaned or moistened. 200.127.59.151 (talk) 01:44, 2 April 2008 (UTC)
- Spiders have compound eyes? They don't look like compound eyes. Is there an anatomy drawing of spider eyes somewhere? 200.127.59.151 (talk) 22:51, 1 April 2008 (UTC)
Another question about spider eyes
[edit]How and why did spiders wind up possessing six-to-eight eyes when most (all the rest of the?) creatures with what we would recognize as a face have only two? I'm looking for a slightly more in-depth answer than "they just evolved that way", if you please. :) --Kurt Shaped Box (talk) 22:44, 1 April 2008 (UTC)
- This site [3] explains that in most species the eyes have different sizes and are thus able to focus at different distances and have different fields of view. The Daylight hunters sections says:
- When hunting, the eyes of jumping spiders see in three different ways, using three different sets of eyes:
- The spider first senses movement of distant prey with the side eyes (PLE), which provide a blurry wide-angle image.
- Once movement is detected, the spider turns in that direction and locks onto the moving prey with the large, middle front eyes (AME). These eyes provide a clear, focussed telephoto image, probably in colour. The spider can track moving prey both by body movements and by using muscles to internally swivel the elongated eye capsules so that the light sensitive retina of each eye remains locked on the prey.
- While the spider stalks closer, it uses the side front eyes (ALE) judge the distance to the prey. When it judges the prey to be close enough (about 2 - 3 cm), the spider leaps.
- And this seems to show that the eyes are organised in formations of three pairs (the side eyes as a double pair). 200.127.59.151 (talk) 23:10, 1 April 2008 (UTC)
Cool about how jumping spiders use their eyes.
I guess the question is, Why do arthropods have multiple eyes, and why have spiders (other than jumping spiders) retained them? I imagine it has something to do with peripheral vision when your eyes (except for jumping spiders) are immobile. Crustaceans have mobile eyes, and AFAIK only two of them. — kwami (talk) 00:12, 2 April 2008 (UTC)
- Can spiders turn their heads independently of their bodies to look at objects, as a matter of interest? If not, this could be another reason for requiring the expanded peripheral vision provided by multiple eyes... --Kurt Shaped Box (talk) 01:33, 2 April 2008 (UTC)
- Unless I misread them, the links say that the spiders only have two body segments and so have to move their body to follow a prey that might leave their field of vision. It also says that appart from rare species, the majority have very poor eyesight relying much more on the vibration in their legs and hair to locate potential preys and threats. Like you said, it does make sense that the distribution of their eyes work as a way of expanding their basic field of view. Add to that the specialisation of each pair of eyes it seems to make a pretty efficient tracking device. Now thinking about how and why their multiple eyes developed in the first place sends my head into a spin. Maybe a good soul could provide us with the name of that spider that manages to scan very complicated paths in space and retain them all in memory before engaging on her journey. 200.127.59.151 (talk) 01:56, 2 April 2008 (UTC)
- Portia. I think I saw the trait that you mentioned in the National Geographic Channel.--Lenticel (talk) 06:50, 2 April 2008 (UTC)
- Unless I misread them, the links say that the spiders only have two body segments and so have to move their body to follow a prey that might leave their field of vision. It also says that appart from rare species, the majority have very poor eyesight relying much more on the vibration in their legs and hair to locate potential preys and threats. Like you said, it does make sense that the distribution of their eyes work as a way of expanding their basic field of view. Add to that the specialisation of each pair of eyes it seems to make a pretty efficient tracking device. Now thinking about how and why their multiple eyes developed in the first place sends my head into a spin. Maybe a good soul could provide us with the name of that spider that manages to scan very complicated paths in space and retain them all in memory before engaging on her journey. 200.127.59.151 (talk) 01:56, 2 April 2008 (UTC)
Multiple eyes
[edit]I'll throw in a third. What other animals have more than two eyes? 200.127.59.151 (talk) 22:55, 1 April 2008 (UTC)
- Depends on your definition of eye (any old photoreceptor cell?), but jellyfish have multiple ways of processing light information, sea stars have little eyes on their end of their stalks, clams have tons of eyes, as do scallops. But these are all pretty simple "eyes", save the scallop, who have lens-bearing eyes. --Captain Ref Desk (talk) 23:46, 1 April 2008 (UTC)
- Ophiocoma wendtii is all eyes, so to speak. Cool, huh? --Kurt Shaped Box (talk) 01:38, 2 April 2008 (UTC)
Very simple eyes (small, lensless, and immobile) are only going to be of use on that part of the body, so you'd need a lot of them to see very much. The question really is, why have so many animal lineages reduced the number of eyes to just two? — kwami (talk) 00:14, 2 April 2008 (UTC)
- My guess would be that eyes are "expensive" from an evolutionary point of view, though I recognize that is something of a tautological statement (durr, they didn't evolve because they didn't evolve). If binocular vision evolved first, then it would make a lot of sense that two eyes was the template on which other eyes were based. Binocular vision is common to most predators, so that wouldn't be too unexpected, and it makes for relatively easy 3-D imaging (not sure how well the brain handles multiple eyes in that respect; even spiders usually have two main, front-facing eyes for that reason). But obviously I'm not speaking with any real knowledge here, just speculation. --Captain Ref Desk (talk) 01:09, 2 April 2008 (UTC)
- Hi. Some jellyfish have "eyes" across their body, but no brain. They will bump into white poles, turn around black poles, and avoid red poles. Don't try picking up even a dead jellyfish, they can still sting, but if you do make sure you pick it up by its bell and not its tenticles (especially if it's a box or irikanji jellyfish), and even if you don't feel anything, they can still be dangerous. Box jellyfish are perhaps one of the most poisonous creatures on Earth (if not the most venomous). They sting with millions of Gs (how do they do that?!). So, anyway, if I remember correctly some have around two dozen "eyes". Source: National Geographic on TVO. Hope this helps. Thanks. ~AH1(TCU) 20:20, 2 April 2008 (UTC)
"Pins and Needles"
[edit]I'm not asking for medical advice, just to be clear. I'm wondering about something I've noticed since I was a child: when one of my legs "falls asleep", part of it "waking up" involves excruciating pain. It's kind of like a paralytic numbness, which apparently is typical, but what's different with me is that that is accompanied by this sort of unbelievably sharp tingling that subsides after a few minutes. I can avoid feeling it very much if I manage to keep my leg perfectly still for a few minutes as its waking up; the slightest shiver or pressure is crippling, though. I'm not at all worried about it, but I'm wondering because I've tried to explain this to friends and no one has ever known what I'm talking about. Any one? Thanks! —Preceding unsigned comment added by 96.232.160.116 (talk) 23:10, 1 April 2008 (UTC)
- Well, "pins and needles" is apparently called paresthesia. It's not abnormal. I suspect the reason your friends don't know about it is because they don't suffer as many "asleep" limbs as you? My legs fall asleep very easily just from sitting in certain positions (my entire butt can even fall asleep), so I am very very familiar with what you describe (it's awful), whereas my wife can count on one hand the amount of times parts of her limbs have fallen asleep, and as a consequence has a much harder time talking about the experience. The page on it says that there are all sorts of horrible conditions that can be associated with but if one just has bad circulation you'd get the same thing (I'm pretty sure mine is just bad circulation, it's been like that since I was a child, and my doctor's tests always come back fine). Anyway, if it helps, I know exactly what you are talking about, I get it all the time, and I too have trouble explaining it to people who don't experience it, as it must be hard to imagine what it's like to have your whole leg (or both legs) feel like they are being jabbed with little sharp implements if you haven't felt it before. --Captain Ref Desk (talk) 23:39, 1 April 2008 (UTC)
Ah, interesting. I looked at the paresthesia page; I should have mentioned that. My friends get "pins and needles" (apparently, that's just the little numbness/tingling everyone gets when a limb falls asleep). The painful pins and needles is either something different, or we're just too sensitive! Knives and daggers maybe... —Preceding unsigned comment added by 96.232.160.116 (talk) 01:02, 2 April 2008 (UTC)
- I notice a distinct difference depending on how "asleep" my leg is. For example, just a minute ago, I had my laptop on my crossed legs for a bit too long and my feet fell asleep. But they weren't very asleep, and "woke up" pretty quickly, and I only had very mild, non-objectionable pins and needles. However when my entire leg falls asleep for some time, usually because I'm cutting off some circulation via my rear (the toilet seat, I must admit, is the most common culprit of this for me—it's almost ideally designed to make my legs fall asleep), then I really get painful pins-and-needles.
- All of which is to say that with my easy-to-fall-asleep legs, I notice lots of variations in how intense the pins and needles are, and it seems to matter (for me) exactly how much circulation I'm cutting off. --Captain Ref Desk (talk) 01:12, 2 April 2008 (UTC)
Earth's magnetic field
[edit]If you loaded a big boat up with permanent magnets or a giant magnetic coil would the boat begin heading for the closest magnetic pole? 71.100.173.69 (talk) 23:12, 1 April 2008 (UTC)
- In theory, yes. In practice, I suspect that even the proverbial boatload of magnets would exert an extremely small pull. Here's why. Once the boat has turned to line up the magnets with the Earth's field, the remaining force will be proportional to the difference in the value of the Earth's field at the two ends of the magnet. A magnet in a uniform field won't feel a force; any force is from the gradient (change) in the field. JohnAspinall (talk) 00:44, 2 April 2008 (UTC)
- Hi. Well, there's also the problem of sinking if the boat gets too heavy, and bumping into land or ice is also a possibility. However, if you magnetise a steel needle, place it into a cork, and float the cork on a tub of water, it will start pointing towards the north pole. Metal objects in water can do some amazing things (besides sink). For example, if I put some paper clips containing metal in water and let the surface tension to float them, they sometimes become attracted to each other, stick together, and even sink to the bottom together. Also, there may be areas in the water in the ocean where methane is released, and causes boats to sink, and people that jump out sink too because the water itself has lost its bouyancy. Hope this helps. Thanks. ~AH1(TCU) 20:27, 2 April 2008 (UTC)
A floating magnet on Earth would experience Torque which would tend to cause it to rotate to align with the Earth'sd magnetic field. It would not move toward the magnet because the repulsion would counteract the attraction. If you could find or create a Magnetic monopole, which no one to date has done, then it would move. Edison (talk) 21:02, 2 April 2008 (UTC)
- You can use the torque of the magnetic spin for propulsion to move you in any direction you wanted, but then you would need to apply energy to move the magnet back away from the direction of the field.--Dacium (talk) 01:38, 3 April 2008 (UTC)
- So to use the Earth's magnetic field for propulsion you would have to somehow use the torque from the spin of the magnet to propel the boat forward instead of just making it point North/South. 71.100.173.69 (talk) 02:54, 4 April 2008 (UTC)
effect of sugar water
[edit]Q What is the effect of sugar water on a plants growth? Bailey504 (talk) 23:15, 1 April 2008 (UTC)
- Might attract hummingbirds for pollination too. --Kurt Shaped Box (talk) 23:27, 1 April 2008 (UTC)
Program to create legal and medical troubleshooting charts
[edit]Not really sure where to put this question since it involves mathematics, science, humanities and business. Anyway here goes... I have written a computer program to apply the method described in Optimal classification for identifying flags to identifying actions. The program can handle a large number of actions, conditions and multiple states, which makes it suitable for use in creating legal and medical troubleshooting charts. All I need to publish such troubleshooting charts are legal and medical logic tables. I could in the alternative publish just the program. How would I go about doing this in the shortest amount of time while preserving my rights to the program? 71.100.173.69 (talk) 23:56, 1 April 2008 (UTC)
- I have no idea what a lot of that means, but a trick for retaining a copyright (besides simply declaring the copyright) that was shared with me by an author some years ago is this: Print a hard copy, and send it by registered mail to yourself. Don't open it. That way, in the event of dispute, a court of law has a federally attested post-mark date by which it can determine the document's correct age. I've never done it, but it sounds reasonable... Vance.mcpherson (talk) 00:16, 2 April 2008 (UTC)
- See Poor man's copyright for why it isn't reasonable. As to the original question, this is basically asking for legal advice, which we aren't allowed to give here. --Anonymous,00:18 UTC, April 2, 2008.
- Since you have not charged me any money I do not think anyone can claim it as legal advice, which would otherwise be a fruadulent claim since clarification of the law is simply not. 71.100.173.69 (talk) 05:51, 2 April 2008 (UTC)
- Clarification - The reference desk will not provide legal advice. This has nothing to do with charging for services. See Wikipedia:Legal disclaimer for further information and explanation. Nimur (talk) 13:56, 2 April 2008 (UTC)
- There are ups and downs to either business model; the one that will likely get you the most profit is also, non-coincidentally, the one that will cost you the most in terms of time and personal investment.
- I deplore software patents (because I think they stifle creativity and are used maliciously) but that's the strongest way to preserve your rights. As for copyrighting the program, that's not hard to do; the hard part about copyrighting is enforcement (that is, it'll be up to YOU to take offenders to court and to prove that they are infringing on your specific code). --Captain Ref Desk (talk) 01:41, 2 April 2008 (UTC)
- Since my objective is to see that both medicine and law are published in the form of a troubleshooting chart the program is only incidental as a means of optimizing the charts. I love free software as well but the reality is that I have worked long and hard to create it at my own expense and without any compensation so I can not in all due respect to myself release it free of charge.
- While software patents may stifle creativity for the end user they may provide incentive and promote creativity for the author. I have copyrighted and published the program and required the user to obtain a key but have since withdrawn the demo and limited versions from publication. Now I'm thinking of using it only as an in house tool and merely offering the service of optimizing any troubleshooting chart. 71.100.173.69 (talk) 05:51, 2 April 2008 (UTC)
- I don't think they stifle creativity with the end user, I think they stifle creativity with other authors. Would you even know if your program infringed upon another software patent, unintentionally? It's entirely possible, that without knowing it, some aspect of your work may have done so. That's the danger of software patents—they aren't like machine patents where you can easily figure out what the prior art is, and the bar for creating new software is a lot lower than creating new engineering methods. I have no problem with authors making money or being successful, but I think software patents make software development and commercialization a legal minefield for all involved (which is why so many companies take out so many software patents just routinely: they're afraid of getting sued by someone else). --Captain Ref Desk (talk) 00:43, 3 April 2008 (UTC)
- The difficultly of assessing who is the rightful owner and who is not may be more difficult for the legal system but all the government really cares about is whatever the software gets published instead of remaining a trade secret for in-house use only. In fact I would prefer to keep it a trade secret and only offer the service it supports rather than publishing it as I have done other stuff cost free and that is what I now think I should do in this case - keep it unpublished as a trade secret. 71.100.173.69 (talk) 03:05, 4 April 2008 (UTC)
- I don't think they stifle creativity with the end user, I think they stifle creativity with other authors. Would you even know if your program infringed upon another software patent, unintentionally? It's entirely possible, that without knowing it, some aspect of your work may have done so. That's the danger of software patents—they aren't like machine patents where you can easily figure out what the prior art is, and the bar for creating new software is a lot lower than creating new engineering methods. I have no problem with authors making money or being successful, but I think software patents make software development and commercialization a legal minefield for all involved (which is why so many companies take out so many software patents just routinely: they're afraid of getting sued by someone else). --Captain Ref Desk (talk) 00:43, 3 April 2008 (UTC)